Cooperative Institute for Research in Environmental Sciences



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Analytical Chemistry Seminar: Dan Hickstein

Analytical Chemistry Seminar: Dan Hickstein

Jointly sponsored by the Department of Chemistry and Biochemistry, CIRES, and the Environmental Program

Uncovering the structure and dynamics of a single nanoparticle  using the world's shortest laser pulses

Dan Hickstein - Kapteyn-Murnane Group, JILA - University of Colorado 

Modern femtosecond lasers can produce pulses of light that are shorter than the vibrational periods in molecules and generate electric fields stronger than the Coulomb field that binds electrons in atoms. These lasers are ideally suited to studying ultrafast processes in nanomaterials, such as electron transfer in photovoltaic nanostructures. However, all previous laser-nanoparticle experiments have been conducted on nanoparticles suspended in solvent, embedded in a bulk material, or attached to a surface, meaning that powerful gas-phase spectroscopy techniques cannot be used. In 2011 we embarked on a collaboration with the Jimenez group to construct a photoelectron–photoion spectrometer capable of examining isolated nanoparticles in the 'gas phase.' To our surprise, the completed spectrometer was capable of recording the complete photoion distribution resulting from the interaction of a single nanoparticle with the femtosecond laser pulse. This breakthrough technique has allowed for the examination of localized light fields in nanostructures, the discovery of shock waves in nanoscale plasmas, and the observation of the evanescent wavefunction in quantum dots. In this talk I describe how we combined the tools of physical chemistry, laser physics, and atmospheric science to construct this new instrument, describe the discoveries to-date, and discuss our plans for future experiments, which include pushing the time-resolution towards the attosecond frontier.

location

CIRES Fellows Room, Ekeley S274 - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-03
 
CSTPR Noontime Seminar: Lucy McAllister

CSTPR Noontime Seminar: Lucy McAllister

Blind Spots: Electronics Firms, and the Social and Environmental Harms of the Electronics Commodity Chain

by Lucy McAllister, Environmental Studies, University of Colorado

Abstract: The global electronics commodity chain perpetuates widespread human and environmental harms, including the global sale of 'conflict minerals' that are used to fund the violence of warlords (Spectrum 2011), the depletion of virgin minerals and precious metals, primarily, from Africa (Boone & Ganeshan 2012), the persistence of unsafe and environmentally hazardous working conditions at electronics factories in Asia (Zhou 2013), and the abridgement of electronics workers' rights to unionize (Cheng et al. 2012). The practices commonly used to recycle electronic waste (e-waste) in the informal sector of developing countries, where roughly 50-80% of the global hazardous e-waste stream is sent, also produce severe harms, including health risks especially for women and children (Frazzoli 2010).

Despite the lead role that multinational electronics firms' likely play in the social and environmental harms of the electronics commodity chain, little research has been done on these issues. The aim of this project is thus to investigate how the specific role of lead firms in producing severe human and environmental problems throughout the electronics commodity chain has gone largely unnoticed by external audiences. Using impression management theory, I will ask whether or how electronics firms use impression management mechanisms to shift attention away from their detrimental business practices, thereby legitimizing themselves in the eyes of the public, and making it easier to sell their products and accumulate capital.

Biography: Before coming to study at the University of Colorado, Boulder, Lucy McAllister graduated summa cum laude from Connecticut College in 2009 with a B.A. in Environmental Studies and German Studies. After college, Lucy spent time in Hamburg, Germany on a Fulbright scholarship and, later, worked at the German Consulate in Chicago, Illinois. Lucy completed her M.S. in environmental studies at CU in May 2013, and has continued within the environmental studies program to pursue a PhD.

Broadly, Lucy explores the business-society-environment relationship, focusing on the role of lead firms in the human and environmental harms of the electronics commodity chain. She was the 2012 Theory in Critical Political Ecology Paper Competition Winner at the University of Kentucky's Dimensions of Political Ecology Conference, and, in the fall of 2013, Lucy was awarded a CIRES Graduate Research Fellowship. Lucy's first article, 'Women, E-waste & Technological Solutions to Climate Change,' was recently published by the Health and Human Rights Journal in June 2014.

location

CSTPR Conference Room, 1333 Grandview Avenue

resources

Event Type

CSTPR
2014-11-03
 
Reading the IPCC Report: Ch. 10 - Detection and Attribution of Climate Change: From Global to Regional by Judith Perlwitz

Reading the IPCC Report: Ch. 10 - Detection and Attribution of Climate Change: From Global to Regional by Judith Perlwitz

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says? This fall's focus is on Climate Change 2013: The Physical Science Basis (Working Group I's contribution to the IPCC 5th Assessment Report)

This is a CIRES-ATOC Seminar Series

For more information please visit: http://cires.colorado.edu/news-events/announcements/new-seminar-series-cires-and-atoc-reading-ipcc-report/

location

CIRES Auditorium - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-04
 
 
 
 
 
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Analytical Chemistry Seminar: Weiwei Hu and Zhe Peng

Analytical Chemistry Seminar: Weiwei Hu and Zhe Peng

Jointly sponsored by the Department of Chemistry and Biochemistry, CIRES, and the Environmental Program

Characterization of a Real-Time Tracer for Isoprene Epoxydiols-Derived Secondary Organic Aerosol (IEPOX-SOA) from Aerosol Mass Spectrometer Measurements

Weiwei Hu et al. - Cooperative Institute for Research in Environmental Sciences, and Department of Chemistry and Biochemistry, University of Colorado, Boulder

Secondary organic aerosol (SOA) can be formed from isoprene epoxydiols (IEPOX), compounds that are produced from isoprene oxidation under low-NO conditions. IEPOX-SOA can account for a substantial fraction of organic aerosol (OA) in biogenic-influenced areas. In this study, IEPOX-SOA was identified from measurements at the forested Southeast U.S. supersite (Centreville, AL) during the Southern Oxidant and Aerosol Study (SOAS) using Positive Matrix Factorization (PMF) of aerosol mass spectrometer (AMS) measurements. The SOAS results clearly show that the fraction of OA measured at C5H6O+ (fC5H6O) in AMS spectra is a good tracer for IEPOX-SOA and correlates with the well-known methyltetrol tracers of this chemistry. Other field and chamber studies are included in the analysis to investigate the robustness of fC5H6O as an IEPOX-SOA tracer in AMS data. We observed clearly higher fC5H6O (3x10-3 - 25x10-3) in OA from regions with strong isoprene emissions vs those from urban and biomass-burning plumes (0 - 3.5x10-3 with an average of 1.75x10-3). In isoprene-influenced areas, fC5H6O in ambient OA positively correlates with the relative contribution of IEPOX-SOA to OA and decreases with OA aging. The kOH for destruction of IEPOX-SOA via heterogeneous oxidation in aerosol phase is approximately 5.3x10-13 cm3 molec1 s1, with life time is around 14.5 days (assuming average OH concentration=1.5x106 molecular cm-3). Volatility analysis using a thermal denuder shows that IEPOX-SOA is not more volatile than bulk SOA, contrasting with the high volatility of the tracers identified. Finally, we develop a simplified method to estimate ambient IEPOX-SOA mass concentrations as a function of fC5H6O, which is shown to perform well compared to the full PMF method. When only unit mass resolution data is available as in ACSM data, the method performs less well because of increased interferences from other ions at m/z 82. Estimated IEPOX-SOA concentrations in the southeastern U.S. from an aircraft campaign (SEAC4RS)correlate well with the IEPOX-related species detected by other techniques over a wide range of conditions, which confirms the usefulness of our method. IEPOX-SOA accounts for 14 - 17% of the OA in the SE U.S. during the summer according to both the SEAC4RS and SOAS results.


Oxidation flow reactors for the study of atmospheric chemistry systematically examined by modeling

Zhe Peng - Cooperative Institute for Research in Environmental Sciences, and Department of Chemistry and Biochemistry, University of Colorado, Boulder

Oxidation flow reactors (OFRs) using OH produced from low-pressure Hg lamps at 254 nm(OFR254) or both 185 and 254 nm (OFR185) are commonly used in atmospheric chemistry and other fields. OFR254 requires the addition of externally formed O3 since OH is formed from O3 photolysis, while OFR185 does not since O3 is formed in the reactor and OH can also be formed from H2O photolysis. In this study, we use a plug-flow kinetic model to investigate OFR properties under a very wide range of conditions applicable to both field and laboratory studies. We show that the radical chemistry in OFRs can be characterized as a function of UV light intensity, H2O concentration, and total external OH reactivity (e.g., from VOCs, NOx, and SO2). In OFR185, OH exposure is more sensitive to external OH reactivity than in OFR254, because injected O3 in OFR254 promotes the recycling of HO2 to OH, making external perturbations to theradical chemistry less significant. There has been some speculation in the literature about whether 'non-tropospheric chemistry' (photolysis at 185 or 254 nm, and/or reactions with O(1D) and O(3P)) may play an important role in these OFRs. For field studies in forested regions or the urban area of Los Angeles, reactants of atmospheric interest are predominantly consumed by OH. Nontropospheric oxidants contribute to the degradation of some species under conditions of low H2O concentration and/or very high external OH reactivity. This appears to have been a problem in some laboratory and source studies, but can be avoided in future studies by experimental planning based on our findings. Some biogenic VOCs can have substantial contributions of reaction with O3 under some operating conditions, especially for OFR254. NO3 may have played an unexpectedly significant role in some past laboratory studies. RO2 fate is similar to that in the atmosphere under low-NOx conditions. A comparison of OFRs with typical environmental chamber studies using UV blacklights and with the atmosphere is presented. OFRs' key advantages are their short experimental time scales, portability to field sites, enabling a direct connection of field and laboratory studies, and controllable and predictable radical chemistry. This study further establishes the usefulness of these reactors and enables better experiment planning and interpretation.

location

CIRES Fellows Room, Ekeley S274 - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-10
 
CSTPR Noontime Seminar: Gesa Luedecke

CSTPR Noontime Seminar: Gesa Luedecke

Let's Hear from the People: A Study on Media Impact on Climate Protection and Climate Adaptation

by Gesa Luedecke, Faculty of Sustainability Sciences, Leuphana University, Lueneburg, Germany

location

CSTPR Conference Room, 1333 Grandview Avenue

resources

Event Type

CSTPR
2014-11-10
 
John Smith Defense

John Smith Defense

Exploration of a whole atmosphere lidar concept for whole atmosphere science: Advances in resonance Doppler lidar technologies

Candidate:  John A. Smith

Adviser: Prof. Xinzhao Chu

Although resonance Doppler lidars have made substantial contributions to our understanding of the mesosphere and lower thermosphere (MLT), today's whole atmosphere models demand a more complete picture which will require mobile instruments with superior resolution and coverage (0-200+ km). Higher resolution is needed to capture smaller scale impacts on transport of energy and momentum in the MLT and greater coverage to understand the ways in which disturbances originating in the lower atmospheres can govern both large and small scale dynamics in the MLT and higher into the thermosphere. A whole atmosphere lidar is needed. Efforts to extend the coverage of wind and temperature in the lower atmosphere with resonance lidars have so far been of limited scientific use since a large gap in coverage still exists where scattering by the Cabannes-Mie/Rayleigh process is too weak and unbound meteoric metals do not extend low enough. Many direct detection techniques suffer from measurement contamination from aerosols also and a measurement sensitivity which can vary depending on the temperature and pressure of the scattering volume, making measurements unreliable. We have a two-pronged approach to address the need for a whole atmosphere instrument in the community.

First, by improving receiver efficiencies of resonance lidars we can reduce photon noise and resolve smaller scale features at higher temporal resolutions. A critical gap in temperatures derived by the Rayleigh lidar technique can be filled by increasing the available signal between where the Rayleigh signal diminishes and where the scattering from resonant species such as Fe picks up in the MLT region. Higher signal levels will also lower the detection threshold for tenuous layers of metal in the thermosphere and enable studies of thermospheric Fe and Na up to 200 km with far better detail. We show how optical design methods and certain alignment considerations were used to improve the sensitivity of existing resonance-fluorescence lidars by several factors. Cases of the implementation of this technique at Boulder, Colorado and Cerro Pachón, Chile show that our procedures in the design and alignment of resonance receivers has improved signal levels by as much as a factor of five - sufficient to directly resolve seasonal vertical eddy flux in the MLT region for the first time and detect extremely tenuous layers of Na in the thermosphere above Cerro Pachón which were previously unstudied.

Second, a novel receiver design concept using a field-widened Mach-Zehnder interferometer (MZI) is investigated which will enable a resonance lidar to conduct wind measurement below the MLT region. The MZI has emerged as a promising direct detection wind technique since it avoids the problem of contamination from aerosols and has been shown to have the best theoretical performance among molecular direct detection techniques. When used in the receiver of an Fe-Doppler lidar system, we show that a particular ratio formulated from the signals in each channel and frequency can be made nearly as sensitive to a unit Doppler shift as the most sensitive implementations of the MZI, yet is also insensitive to aerosol backscatter ratio and temperature and pressure of the scatter volume. Summation of the two channels results in a signal which is independent of the intermediate MZI and can therefore be used harmoniously with the existing resonance Doppler 3-frequency technique, thereby enabling routine coverage of wind from the near surface to more than 115 km with a single lidar. The implications for such measurements are an improved understanding of, for example, gravity wave spectra propagation, Brewer-Dobson circulation and the 'cold pole' problem and the tracing of inertia gravity waves to their source regions.

location

CIRES Auditorium, Rm 338 - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-10
 
Reading the IPCC Report: Ch. 4 - Observations: Cryosphere by Tad Pfeffer

Reading the IPCC Report: Ch. 4 - Observations: Cryosphere by Tad Pfeffer

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says? This fall's focus is on Climate Change 2013: The Physical Science Basis (Working Group I's contribution to the IPCC 5th Assessment Report)

This is a CIRES-ATOC Seminar Series

For more information please visit: http://ciresweb.colorado.edu/news-events/announcements/new-seminar-series-cires-and-atoc-reading-ipcc-report/

location

CIRES Auditorium - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-11
 
Global Challenges and Good Governance: Can Sport Deliver?

Global Challenges and Good Governance: Can Sport Deliver?

Global Challenges and Good Governance: Can Sport Deliver?

Wednesday, November 12 at 4:00 PM
Eaton Humanities, Room 135

A talk by Jens Sejer Andersen
Danish Institute for Sports Studies, Aarhus, Denmark
journalist, international director and founder of Play the Game
More Info

Across the Western Hemisphere, a crisis of public confidence is shaking the International Olympic Committee and the international federations that deliver the Olympic competitions. At various referendums and public debates, taxpayers reject the prospect of bidding for future Olympics. Match-fixing with or without relation to gambling crime has caused police and governments to react worldwide. The doping industry continues to play cat-and-mouse with international controllers. FIFA and other governing bodies are regularly exposed for corruption, mismanagement and rigged elections. How can international sport get out of its political quagmire? One essential requirement is better governance in the international sports organisations, but the governing bodies that control world sport are reluctant to change. Play the Game's advocacy for good governance in sport has positioned the initiative and the biennial Play the Game conference as a leading voice for democracy, transparency and freedom of expression in international sport. Play the Game's founder and international director Jens Sejer Andersen will outline a number of current corruption cases in international sport and present some attempts to remedy the situation, among others the Sports Governance Observer, a benchmarking tool developed in cooperation with six European universities.

location

Eaton Humanities, Room 135 - University of Colorado Boulder, Boulder, CO 80309
2014-11-12
 
 
 
 
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Analytical Chemistry Seminar: Theodore Koenig

Analytical Chemistry Seminar: Theodore Koenig

Iodine Monoxide observations from CU AMAX-DOAS aboard the NSF NCAR GV research aircraft

Theodore Koenig

The CU Airborne Multi-AXis Differential Optical Absorption Spectroscopy (CU AMAX-DOAS) instrument was deployed for the TORERO and CONTRAST field campaigns. These were in the Tropical Eastern Pacific in January-February 2012, and the Tropical Western Pacific in January-February 2014 respectively. We report the first scattered light limb measurements of IO. I will discuss a number of highlights from our observations: 1) instances of enhanced IO mixing ratios in the transition layer 2) a free troposphere background of IO that shows little variation with altitude 3) a hemispheric gradient in total IO column and 4) the first quantification of IO in the lower stratosphere. These measurements provide the best constraints to date on IO outside the planetary boundary layer. They offer the chance to begin assessing our understanding on iodine chemistry in the transition layer, free troposphere, and lower stratosphere and its impacts of climate, particularly tropospheric ozone.

Jointly sponsored by the Department of Chemistry and Biochemistry, CIRES, and the Environmental Program

2014-11-17
 
CSTPR Noontime Seminar: Kritee Kritee

CSTPR Noontime Seminar: Kritee Kritee

Climate Smart Agriculture in Asia: Measurements, Implementation Strategy and Challenges

by Kritee Kritee, Senior Scientist, International Climate, Environmental Defense Fund

Watch the webcast live

 

Biography: Kritee is a part of Environmental Defense Fund's international climate team that is linking farmers to the carbon market in ways that promote mitigation, support development in the rural economy, accelerate poverty alleviation, and strengthen adaptation to the effects of climate change. She is helping lay the groundwork for agricultural carbon offset protocols for small land holdings by directing a multi-partner research team at the five GHG (nitrous oxide and methane) measurements laboratories across three states in Southern India. This research team is examining the effectiveness of innovative farming practices in delivering the three-fold goal of increased crop yields, better farm economics and decreased GHG emissions. She also provides scientific input to EDF's domestic legal teams' efforts to improve government policies related to the energy sector, with a focus on mercury pollution from electric generation units.

location

CSTPR Conference Room, 1333 Grandview Avenue

resources

Event Type

CSTPR
2014-11-17
 
Reading the IPCC Report: Ch. 9 - Evaluation of Climate Models by Clara Deser

Reading the IPCC Report: Ch. 9 - Evaluation of Climate Models by Clara Deser

Ever wonder what the Intergovernmental Panel on Climate Change (IPCC) report says? This fall's focus is on Climate Change 2013: The Physical Science Basis (Working Group I's contribution to the IPCC 5th Assessment Report)

This is a CIRES-ATOC Seminar Series

For more information please visit: http://cires.colorado.edu/news-events/announcements/new-seminar-series-cires-and-atoc-reading-ipcc-report/

location

CIRES Auditorium - 1665 Central Campus Mall, Boulder, CO 80309
2014-11-18
 
 
 
Colorado Science Conference

Colorado Science Conference

Come visit our booth (#403) at the Colorado Science Conference. For more information, please visit: http://www.coloradocast.org/professionaldevelopment.php?page=overview

location

Denver Merchandise Mart - East 58th Avenue, Denver, CO
2014-11-21
 
 
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